Implement AudioParamMap

AudioParamMap is a map-like container owned by AudioWorkletNode object.
It associates the name of a parameter to the actual AudioParam object.

Spec: https://webaudio.github.io/web-audio-api/#idl-def-AudioParamMap

Bug: 736781
Change-Id: I063add4281954036b90442dc5c4a6e9c50145e41
Reviewed-on: https://chromium-review.googlesource.com/548239
Commit-Queue: Hongchan Choi <hongchan@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Raymond Toy <rtoy@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486007}

third_party/WebKit/LayoutTests/virtual/service-worker-navigation-preload-disabled/webexposed/global-interface-listing-expected.txt

@@ -346,6 +346,17 @@ interface AudioParam
     method setValueAtTime
     method setValueCurveAtTime
     setter value
+interface AudioParamMap
+    attribute @@toStringTag
+    getter size
+    method @@iterator
+    method constructor
+    method entries
+    method forEach
+    method get
+    method has
+    method keys
+    method values
 interface AudioProcessingEvent : Event
     attribute @@toStringTag
     getter inputBuffer

third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt

@@ -346,6 +346,17 @@ interface AudioParam
     method setValueAtTime
     method setValueCurveAtTime
     setter value
+interface AudioParamMap
+    attribute @@toStringTag
+    getter size
+    method @@iterator
+    method constructor
+    method entries
+    method forEach
+    method get
+    method has
+    method keys
+    method values
 interface AudioProcessingEvent : Event
     attribute @@toStringTag
     getter inputBuffer

third_party/WebKit/Source/modules/modules_idl_files.gni

@@ -290,6 +290,7 @@ modules_idl_files =
                     "webaudio/AudioListener.idl",
                     "webaudio/AudioNode.idl",
                     "webaudio/AudioParam.idl",
+                    "webaudio/AudioParamMap.idl",
                     "webaudio/AudioProcessingEvent.idl",
                     "webaudio/AudioScheduledSourceNode.idl",
                     "webaudio/AudioWorkletGlobalScope.idl",

third_party/WebKit/Source/modules/webaudio/AudioParamMap.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/webaudio/AudioParamMap.h"
+
+namespace blink {
+
+class AudioParamMapIterationSource final
+    : public PairIterable<String, AudioParam*>::IterationSource {
+ public:
+  AudioParamMapIterationSource(
+      const HeapHashMap<String, Member<AudioParam>>& map) {
+    for (const auto name : map.Keys()) {
+      parameter_names_.push_back(name);
+      parameter_objects_.push_back(map.at(name));
+    }
+  }
+
+  bool Next(ScriptState* scrip_state,
+            String& key,
+            AudioParam*& audio_param,
+            ExceptionState&) override {
+    if (current_index_ == parameter_names_.size())
+      return false;
+    key = parameter_names_[current_index_];
+    audio_param = parameter_objects_[current_index_];
+    ++current_index_;
+    return true;
+  }
+
+  DEFINE_INLINE_VIRTUAL_TRACE() {
+    visitor->Trace(parameter_objects_);
+    PairIterable<String, AudioParam*>::IterationSource::Trace(visitor);
+  }
+
+ private:
+  // For sequential iteration (e.g. Next()).
+  Vector<String> parameter_names_;
+  HeapVector<Member<AudioParam>> parameter_objects_;
+  unsigned current_index_;
+};
+
+AudioParamMap::AudioParamMap(
+    const HeapHashMap<String, Member<AudioParam>>& parameter_map)
+    : parameter_map_(parameter_map) {}
+
+PairIterable<String, AudioParam*>::IterationSource*
+    AudioParamMap::StartIteration(ScriptState*, ExceptionState&) {
+  return new AudioParamMapIterationSource(parameter_map_);
+}
+
+bool AudioParamMap::GetMapEntry(ScriptState*,
+                                const String& key,
+                                AudioParam*& audio_param,
+                                ExceptionState&) {
+  if (parameter_map_.Contains(key)) {
+    audio_param = parameter_map_.at(key);
+    return true;
+  }
+
+  return false;
+}
+
+}  // namespace blink

third_party/WebKit/Source/modules/webaudio/AudioParamMap.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef AudioParamMap_h
+#define AudioParamMap_h
+
+#include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/Maplike.h"
+#include "bindings/core/v8/V8BindingForCore.h"
+#include "modules/webaudio/AudioParam.h"
+#include "platform/bindings/ScriptWrappable.h"
+#include "platform/heap/Handle.h"
+#include "platform/wtf/text/WTFString.h"
+
+namespace blink {
+
+class AudioParam;
+
+class AudioParamMap final : public GarbageCollectedFinalized<AudioParamMap>,
+                            public ScriptWrappable,
+                            public Maplike<String, AudioParam*> {
+  DEFINE_WRAPPERTYPEINFO();
+
+ public:
+  explicit AudioParamMap(
+      const HeapHashMap<String, Member<AudioParam>>& parameter_map);
+
+  // IDL attributes / methods
+  size_t size() const { return parameter_map_.size(); }
+
+  AudioParam* At(String name) { return parameter_map_.at(name); }
+  bool Contains(String name) { return parameter_map_.Contains(name); }
+
+  DEFINE_INLINE_VIRTUAL_TRACE() { visitor->Trace(parameter_map_); }
+
+ private:
+  PairIterable<String, AudioParam*>::IterationSource* StartIteration(
+      ScriptState*,
+      ExceptionState&) override;
+  bool GetMapEntry(ScriptState*,
+                   const String& key,
+                   AudioParam*&,
+                   ExceptionState&) override;
+
+  const HeapHashMap<String, Member<AudioParam>> parameter_map_;
+};
+
+}  // namespace blink
+
+#endif

third_party/WebKit/Source/modules/webaudio/AudioParamMap.idl

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://webaudio.github.io/web-audio-api/#idl-def-AudioParamMap
+[
+  RuntimeEnabled=AudioWorklet
+] interface AudioParamMap {
+    readonly maplike<DOMString, AudioParam>;
+};

third_party/WebKit/Source/modules/webaudio/BUILD.gn

@@ -32,6 +32,8 @@ blink_modules_sources("webaudio") {
     "AudioNodeOutput.h",
     "AudioParam.cpp",
     "AudioParam.h",
+    "AudioParamMap.cpp",
+    "AudioParamMap.h",
     "AudioParamTimeline.cpp",
     "AudioParamTimeline.h",
     "AudioProcessingEvent.cpp",